CAPILLARY GAS-CHROMATOGRAPHIC RETENTION BEHAVIOR AND PHYSICOCHEMICAL PROPERTIES OF UNDERIVATIZED EQUINE ESTROGENS

The capillary gas-chromatographic retention behavior of six underivati zed equine estrogens (estrone, equilin, equilenin and their correspond ing 17 alpha-diols) on a mixed stationary phase (non-polar CP-Sil 5 CB and slightly polar CP-Sil 19 CB capillary columns coupled in series) was characterized by their Kovats retention indices and steroid number s. In order to find whether a correlation exists between the chromatog raphic retention and some physico-chemical properties of the compounds , their octanol-water partition coefficients and dipole moments were m easured. No straightforward correlation was observed between the physi co-chemical properties and the retention behavior, which suggests that the GC separation of equine estrogens is governed by some specific el ectron donor-electron acceptor interactions of a chemical nature.